Modified short-course fludarabine-based conditioning regimen for salvage cord blood transplantation after graft...

Graft failure after allogeneic hematopoietic stem cell transplantation is a life-threatening complication requiring retransplantation. Cord blood is frequently used in this setting, although the optimal conditioning regimen remains unclear. Recently, a modified short-course fludarabine-based conditioning regimen has been used in clinical practice for salvage cord blood retransplantation in Japan.Using Japanese registry data, we analyzed 465 patients with hematologic malignancies who developed graft failure and underwent cord blood retransplantation within 2 months after allogeneic hematopoietic stem cell transplantation between 2008 and 2016. Of these, 84 patients received a modified short-course fludarabine-based conditioning regimen consisting of fludarabine 30 to 90 mg/m² over 1 to 3 days, cyclophosphamide 2 g/m², and low-dose total body irradiation (2 Gy).One-year overall survival and progression-free survival were higher with the modified short-course regimen than with other regimens (45.1% vs 29.9%, p = 0.028; 44.0% vs 26.8%, p = 0.008, respectively). Engraftment at day 56 did not differ significantly between groups (64.3% vs 57.4%, p = 0.178).The modified short-course regimen was associated with improved overall and progression-free survival and may represent a feasible option for salvage cord blood retransplantation after graft failure.